bimap package:streaming

bimap :: Bifunctor p => (a -> b) -> (c -> d) -> p a c -> p b d
streaming Streaming
Map over both arguments at the same time. 
bimap f g ≡ first f . second g

Examples

>>> bimap toUpper (+1) ('j', 3)
('J',4)

>>> bimap toUpper (+1) (Left 'j')
Left 'J'

>>> bimap toUpper (+1) (Right 3)
Right 4